Energy for Muscle Contraction Direct Phosphorylation Aerobic Respiration Anaerobic Glycolysis

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Text of Energy for Muscle Contraction Direct Phosphorylation Aerobic Respiration Anaerobic Glycolysis

  • Energy for Muscle ContractionDirect PhosphorylationAerobic RespirationAnaerobic Glycolysis

  • VocabularyAponeurosis: A sheetlike fibrous membrane that binds muscles together or as a means of connecting muscle to bone.Motor Unit: A single motor neuron and all the muscle fibers it stimulates.Ligament: A sheet or band of tough, fibrous tissue connecting bones or cartilages at a joint

  • VocabularyEpimyusium: The external sheath of connective tissue surrounding a muscle. (outermost)Perimysium: The fibrous sheath enveloping each of the primary bundles of skeletal muscle fibers. (Middle)Endomysium: The connective tissue layer surrounding an individual skeletal muscle fiber. (Innermost)

  • Direct PhosphorylationUses Creatine Phosphate Found only in muscle Regenerates ATP from ADPCP exhausted in 20 secondsNo Oxygen Used

  • Aerobic RespirationGenerates ATP in mitochondriaUses OxygenOxidative PhosphorylationGlucose is broken down to CO2 and H2O36 ATP per 1 glucoseSlow processLasts for hours

  • Anaerobic RespirationGlycolysis uses no oxygenOccurs in cytosolBroken down to pyruvic acid which is converted to lactic acid when oxygen cannot keep up to demand2 ATP per glucose30-60 seconds

  • Energy SourcesFirst: GlucoseSecond: Pyruvic AcidThird: Fatty Acids stored in adipose tissueFourth: Amino Acids from protein catabolism

  • Muscle FatigueMuscle cannot contract even when stimulatedWeaker and weaker until it stopsResults from Oxygen debtBuild up of lactic acid and lack of creatine phosphate and ATP reserves

  • Oxygen DebtProlonged workoutsOxygen uptake can no longer keep upResults in rapid or deep breathingMuscle may quit entirely

  • Hitting the WallBonkGlycogen depletionExtreme fatigueRemedied by carbohydrates

  • MovementsFlexionExtensionHyperextension

  • Movements


  • MovementPlantar FlexionDorsiflexion

  • MovementRotationMedial RotationLateral Rotation

  • MovementSupinationPronation

  • MovementInversion Eversion

  • Review Sarcomere

  • More Vocabulary:Sarcolemma: Plasma membrane of a muscle cellMyofibril: Long organelles that fill the cell and are composed of myofilamentsMyofilaments: threadlike protein fibersThick filaments = MyosinThin Filaments = Actin

  • Muscle Characteristics Skeletal: Multinucleate, Striated, Long Thin Cells. Attached to bones. Voluntary

    Cardiac: Branched, Uninucleate, Striated, Intercalated discs. Walls of Heart. Involuntary

    Smooth: Fusiform (tapered), Uninucleate, No striations. Involuntary.

  • VocabularyA Bands = Dark bands of a myofibrilI Bands = Light bands of a myofibrilZ Disc or Z Band= Interruption in the center of the I BandM Line: Holds thick filaments together and can be seen in the center of the H zoneH Zone: Light central area of sarcomere that lacks actin (also bare zone) this disappears during contraction when fibers overlap

  • Muscle Contraction ReviewMotor neuron is stimulated and the action potential travels along the neuron.

  • Muscle Contraction2. Acetylcholine is released from the neuron end plate into the neuromuscular junction

  • Muscle Contraction3.Acetylcholine diffuses across the neuromuscular junction gap

  • Muscle Contraction4. The muscle fiber membrane is stimulated, impulse travels through transverse tubules to sarcoplasmic reticulum

  • Muscle Contraction5. Sarcoplaspic reticulum releases Ca+2 into the sarcoplasma

  • Muscle Contraction6. Calcium binds to troponin on the actin (thin) filaments allowing myosin (thick) filaments to form cross-bridges

  • Muscle Contraction7&8 Power Stroke occurs and repeats as long as calcium is present and the muscle shortens

  • Muscle Contraction9. Motor neuron stimulation stops. Cholinesterase causes the breakdown of acetylcholine

  • Muscle Contraction10. Calcium ions are pumped out into the sarcoplasmic reticulum using active transport

  • Muscle Contraction11& 12 Linkages between actin and myosin are released. The muscle relaxes to its pre-stimulated length

  • Quiz Tuesday Muscle Physiology